Yes, it very much is! In fact, I landed there yesterday ending a 9 month deployment.
NAS JAX is home to a handful for helicopter and P-8 (which are the P-3 replacements) squadrons.
Mayport is coming back to life as well with the addition of some Amphibs to be homeported there.
I went to AE A School at Jacksonville in 1970. They moved all the schools to Memphis.